vulnerability to PROJ6/GDAL3

[rsbivand]

Running revdeps from sp (sp (my github fork) with development rgdal from R-Forge):

> packageVersion("sp")
[1] ‘1.3.4’
> packageVersion("rgdal")
[1] ‘1.5.3’
> rgdal::rgdal_extSoftVersion()
          GDAL GDAL_with_GEOS           PROJ             sp 
       "3.0.2"         "TRUE"        "6.2.1"        "1.3-2" 

a test fails:

> test_check("PWFSLSmoke")
  ── 1. Failure: arguments are validated (@test-timeinfo.R#19)  ──────────────────
  `timeInfo <- timeInfo(datetime, longitude, latitude)` produced warnings.
  
  ══ testthat results  ═══════════════════════════════════════════════════════════
  [ OK: 41 | SKIPPED: 2 | WARNINGS: 16 | FAILED: 1 ]
  1. Failure: arguments are validated (@test-timeinfo.R#19) 

See:

http://rgdal.r-forge.r-project.org/articles/PROJ6_GDAL3.html
r-spatial/sf#1231
r-spatial/sf#1187
r-spatial/sf#1146
r-spatial/discuss#28

for background. See:

r-spatial/discuss#28 (comment)

for a way of testing fixes in a docker container contributed by Jakub Nowosad.

[rsbivand]

Problems still present, rgdal to be released soon.

[rsbivand]

At least test-timeinfo.R line 19:

  # Should determine timezone from datetime if no timezone is provided
  expect_silent( timeInfo <- timeInfo(datetime, longitude, latitude) )

is broken. Do not use expect_silent unless you really control all of the package functions and their external dependencies.

[jonathancallahan]

Removed expect_silent() as unnecessary and incorrect.

Thanks to rsbivand for the specific suggestion.